Thomas Malthus fretted about over-population and it's effect on the poor. This social fear was real in his days. Fear of the workhouse and becoming a ward of the state was profiled in the setting of the BBC series"Downton Abbey" 90 years after Malthus' death. There, in the 1920s, we see the character Thomas in utter despair about losing his position at the mansion without a reference. He was truly destined for the dark-grey, sluggardly world of early 20th century social security, the workhouse: separating burrs from raw wool, seeds from cotton, or punching out buttons, all by hand, for a state handout, till death. Poverty was truly Malthus' concern. Population versus resources is our impending critical dilemma. The world has the money to feed everyone, but it's distribution is the problem. This issue may never be resolved, given greed, and the perceived need to hold on to whatever power money brings. Will ever our food production be enough remains to be seen. Poverty, being the horror that it is, is supported somewhat by the state, birth control is not. We are facing the production of food being outrun by the need for it. Whenever a population is stressed by lack of anything critical, much less precious-like electricity, it moves to fill that void. Overpopulation will be the worst type of collapse, because it won't so well be seen coming. It is too surreal to imagine limiting the growth. India and China made inroads to state ordained birth control. These efforts were born from unique political situations. To do so on a world basis, especially in the spoiled free countries of western democracy is a pipe-dream at best. So, poor money control; no political will to encourage limited population growth; the question: are we ever going to grow enough; are all issues. Will we be able to feed the folks? I believe this pending cause of world collapse will creep upon us like the 600' dust cloud of the Midwest's Dust Bowl. One day it will be upon us and we won't be prepared. Mr. Malthus's ghosts of the 19th century will become our zombies, wandering lost for simple sustenance.

I just have to point out that birth control is free in the United Kingdom and our birth rate is 1.98 which is less than replacement rate. In the US it's 1.89 and Germany 1.32. So to blame things on the "spoiled west" is perception not fact because given the chance a great many women will self-limit their number of pregnancies without compulsion. The main demographic danger facing us is actually not having enough young people to support our elders.

Poorer countries have higher birthrates but they also have higher death rates.

Which isn't to say that we aren't in danger of an overpopulation crisis. If population keeps growing we will eventually reach carrying capacity but at the moment the possibility that even with improved medicine global death rate might eventually exceed global birth rate is just as possible. It took several years longer than expected to pass the seven billion mark because population growth had slowed.

Population vs resources and logistics is a far more serious problem. When we run out of oil how are we going to move things from where they are to where they are needed? What if something else disrupts the global trade network or a crisis hits the world's big food exporters? Britain has a dense population and has been a net importer of food for a very long time (hence the Battle of the Atlantic in WWII) and currently imports around 40% of its food. Some of that shortfall could no doubt be dealt with via rationing, decreased food waste and increased agricultural production but it's not at all clear if all of it could. The US by contrast is a net exporter of food and as long as it could still transport food around the country (by no means certain given its size) it would do better in that situation.